I think people have gone way too far out on freebore. .100 is plenty for up to Berger 108s. So, ultimately the Noram reamer is perfect for 80-108s.
As we discussed before the real problem is that everyone is using too tight of necks
Problem? I think a lot of people cut thinner than they have to, but the trend is to thicker necks...err minimal turn necks. Tighter, to me, relates to clearance. That's something we are in full control of if we turn necks. I like to use about .003" on most stuff. Sometimes a touch more on big stuff. I see it mostly as a factor to brass life. Working the brass less, yields better brass life. And then there is annealing...
Whole 'nother subject.
Too little clearance is IMO, a fools errand. It gains little if anything at all but can cause accuracy as well as safety problems, if too tight. I've never tested specifically to see how much it affects brass life but have routinely gotten very good brass life with very high pressure loads and a good fit between die and chamber. The last time I did anything that told me much about my brass life, I went 50 firings on Lapua Grendel brass, annealing once at about half of that. I pushed it a little far and the brass literally started causing the gun to double group..of all things. I think it would be safe to say that brass was good for 40+ firings easy enough though. Probably closer to 45 or 46. These were not pussycat loads, either. Primer pockets loosened a bit early, then pretty much stabilized for most of the rest of the time. I culled some as pockets got where they were too loose. I will say this...YMMV, but a good die to chamber fit and Lapua brass is tough stuff....or it was then. That was in about 2009ish. I've not pushed brass that long in a long time.
I don't like to run too much clearance but I don't think it hurts accuracy until the necks begin to work harden. Some people run more and some less. More people anneal now, too. Again, at the other extreme but, little if anything to gain and is a waste of brass life, to run too much clearance, i.e., .006 or more. Neck tension is a factor too. If we are running a lot of tension, we are moving the brass to size it down, then the bullet just opens it back up. Lots of work on the brass. Ultimately, we tend to do what we believe works best though. Hard to argue with results.
Several factors to good brass life. You can ruin it in one firing with too much pressure so I guess it's safe to assume pressure is the most important factor.
As to freebore and using as little as possible, you're also using up case capacity if the bullet seats way deeper than necessary. Nothing wrong with slightly compressed charges but compressing it too much creates another set of problems, like bullets pushing out and effectively slowing the powder burn rate down some. I like for the base of the bullet to lightly compress the powder, to the point that if you pour it through a long drop tube, it's still in contact with the bullet base. Maybe it's splitting hairs, but it matters in an all out BR rifle, IMO. Lots of things that some do, IMO, does not, but if we think it matters...then it certainly does matter. Throating for optimal powder capacity is something that I believe is worthwhile in a BR rifle but likely not, in anything else.
